im not sure how well it works in a 350 but in my last 5.0 mustang i had the no top end problem due to 4:11 gears out back. i put a main bearing girdle on down low, upgraded to a fluidamper vibration dampner, and put in stronger double spring valve springs to eliminate valve floating at high r.p.m. . im sure that the springs did all the extra work as far as getting me the extra rpm's but i still thought it was worth the money for the safety of the girdle and dampner. it wasnt a huge gain like a tranny might get you if its set up right, but if youre budget minded and dont run it balls to the wall all the time its not a bad set up. on the other hand if you could find a used tranny and torque convertor in good shape it might all be pretty close money wise.